The use of aerospikes at the nose of a hypersonic vehicle can substantially reduce its drag; however, the associated heat flux at the reattachment point is very high for turbulent flows. In this paper, the aerothermodynamics of a generic projectile model represented by a hemisphere-cylinder, fitted axisymmetrically with an aerospike at the nose is investigated numerically with a commercially available Navier Stokes Solver. The base model is a hemisphere-cylinder with a diameter of 40mm and an overall length of 70mm. An aerospike protrudes axisymmetrically at the nose of the base model and has a hemispherical cap from which another aerospike protrudes which again has a hemispherical cap, thus forming a double-disk aerospike. Compressible, axisymmetric NavierStokes Equations are solved for turbulent hypersonic flow of thermally perfect air with free stream conditions of Mach No 6·2 at standard sea level atmospheric conditions. The results for the model with double-disk aerospikes are compared with those of hemisphere-cylinder without aerospike. The results suggest that the use of double-disk aerospike can favourably reduce the turbulent reattachment heat flux along with suitable drag reduction of the main body.

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Numerical experiments are carried out using commercially available Navier–Stokes solver to investigate the effect of forward-facing parabolic cavity on the heat fluxes over a spherical nosed blunt body. A wide range of parabolic cavities with depths varying between 2 and 10 mm placed at the nose of sphere-cylinder with base diameter 40 mm and overall length 70 mm have been investigated. The ratio of the cavity radius at intersection with y-axis to depth of cavity ( r/d) of these cavities varies from 1.5 to 2.5. All computations have been done at a freestream Mach number of 6.2 and sea level atmospheric conditions assuming air to be a thermally perfect gas. The steady-state solutions obtained through time marching solution of axisymmetric Navier–Stokes equations suggest that the total heat transfer rate, area weighted average heat flux and the peak heat fluxes to the body can be favorably reduced for shallow parabolic cavities.

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